The present invention relates to pivotal connections of a bicycle derailleur between a parallelogram and either a base member connected to a bicycle frame or a chain cage for guiding a bicycle chain.
DE 101 57 213 A1 discloses a bicycle rear derailleur with a pin-mounted parallelogram. Links of the parallelogram are connected to a base member and to a chain cage by inserting pivot pins into aligned bores of one of the links and one of the base member and the chain cage. To prevent the pivot pins from axially displacing, a securing ring is snapped into a groove on the pivot pin. In one embodiment, the securing ring is axially supported on the parallelogram link and on the base member or the chain cage. In another embodiment, the securing ring is arranged in a recess in the parallelogram link that is laterally supported in a recess in the base member or the chain cage.
One drawback of the above pivot connection between the parallelogram link and the base member or the chain cage is that it does not have any defined bearing surfaces, resulting in the pivot pin rotating in the base member or the chain cage as well as in the parallelogram link. Further, there is no covering over either end of the pivot pin, such that dirt is not prevented from entering between the pin and the mounting bore.